1. Field of the Invention
The present invention relates to sensors for monitoring whether or not fasteners are sufficiently engaged for safe operation before a process is initiated. In particular, tank portholes that receive pipe connections, probes or other processing equipment are held in place by a clamp, collar or other means. The clamp, collar or other means must be properly physically engaged in order to assure safe operation. An embodiment of the present invention comprises one or more sensors tied or connected to indicators and/or the process control system such that disengaged or improperly/incompletely engaged couplings can be detected before a process is initiated.
2. Description of Background Art
Probes, valves and feed and drain lines can be connected to the ports of pharmaceutical processing equipment tanks using a wide range of couplings. The two most common types of connection systems includes a threaded retaining collar fitted over a flange or shoulder and coupled to mating threads or a pair of mating flanges coupled using bolts or a clamping device. The coupling devices are commonly used because they have been proven both reliable and effective at maintaining the juxtaposition of opposing members and the seal formed between them or by their coupling. If these systems fail, however, the consequences can be very costly in terms of damage to equipment, losses in time and materials and, most importantly, injury to people. As a consequence, significant efforts have been taken to establish SOPs (or “standard operating procedures”) that include checking and rechecking for the proper placement of couplings on processing equipment before a process is initiated. Operators are trained and retrained on these procedures and supervisors supervise operators during operations all in an effort to keep all types of failures from occurring, including coupling failures. In spite of these efforts, failures continue to occur.
Recently, a means to assure that couplings, once made, would not fail was sought. However, as mentioned above, the failures that occur are not normally associated with the couplings themselves but, rather, their installation or lack thereof. In fact, it is frequently the failure of the operator to engage the coupling that is the cause of the process leak that occurs. Specifically, in the case of sanitary processing, clamps are placed over flanges but they are not fully engaged. Valves, probes or other equipment are attached to or installed into ports, but the threaded collar or coupling is either not introduced, is present but is not engaged or is not sufficiently engaged. The purpose of the present invention is to give the operator, supervisor or monitor of the process an indication that a coupling is not properly completed or, at least in some cases, may be failing.